#ifndef _GETOPT_H
#define _GETOPT_H


#ifdef __cplusplus
extern "C" { 
#endif 

    /* For communication from `getopt' to the caller.
    When `getopt' finds an option that takes an argument, 
    the argument value is returned here.
    Also, when `ordering' is RETURN_IN_ORDER, 
    each non-option ARGV-element is returned here.*/

    extern char *optarg; 

    /* Index in ARGV of the next element to be scanned.
    This is used for communication to and from the caller 
    and for communication between successive calls to `getopt'. 

    On entry to `getopt', zero means this is the first call; initialize.

    When `getopt' returns -1, this is the index of the first of the 
    non-option elements that the caller should itself scan. 

    Otherwise, `optind' communicates from one call to the next
    how much of ARGV has been scanned so far.*/ 

    extern int optind; 

    /* Callers store zero here to inhibit the error message `getopt' prints
    for unrecognized options.*/ 

    extern int opterr; 

    /* Set to an option character which was unrecognized.*/

    extern int optopt; 

    /* Describe the long-named options requested by the application. 
    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
    of `struct option' terminated by an element containing a name which is
    zero. 

    The field `has_arg' is: 
    no_argument(or 0) if the option does not take an argument,
    required_argument(or 1) if the option requires an argument, 
    optional_argument(or 2) if the option takes an optional argument. 

    If the field `flag' is not NULL, it points to a variable that is set
    to the value given in the field `val' when the option is found, but 
    left unchanged if the option is not found.

    To have a long-named option do something other than set an `int' to 
    a compiled-in constant, such as set a value from `optarg', set the
    option's `flag' field to zero and its `val' field to a nonzero
    value (the equivalent single-letter option character, if there is 
    one).For long options that have a zero `flag' field, `getopt' 
    returns the contents of the `val' field.*/

    struct option
    {
#if defined (__STDC__) && __STDC__ 
        const char *name;
#else
        char *name;
#endif 
        /* has_arg can't be an enum because some compilers complain about
        type mismatches in all the code that assumes it is an int.*/
        int has_arg; 
        int *flag; 
        int val; 
    }; 

    /* Names for the values of the `has_arg' field of `struct option'.*/ 

#define no_argument 0
#define required_argument 1
#define optional_argument 2

    extern int getopt_long (int argc, char *const *argv, const char *shortopts,
        const struct option *longopts, int *longind);
    extern int getopt_long_only (int argc, char *const *argv,
        const char *shortopts,
        const struct option *longopts, int *longind); 

    /* Internal only.Users should not call this directly.*/
    extern int _getopt_internal (int argc, char *const *argv,
        const char *shortopts,
        const struct option *longopts, int *longind,
        int long_only); 
    extern int
        getopt (int argc,
        char *const *argv,
        const char *optstring);

#ifdef __cplusplus
}
#endif 

#endif /* _GETOPT_H */ 